Recent advances in porcine genomics have identified quantitative trait loci (QTL) that influence pork production traits such as carcass traits, meat quality, and reproductive efficiency (Rohrer 2000; Cassady 1999). The low resolution to which most of these loci have been defined precludes the accurate application of markerassisted selection (MAS) strategies for increasing production efficiency. Large-insert genomic libraries are an excellent resource for marker development aimed at increasing the resolution of QTL and for the development of contiguous physical maps (contigs) of the chromosomal regions containing them